used regular. And if the printer is near a radiator even quciker. The Ink itself has not dried up but most likley to be the Cart ink head.
Do you have the Cleaning fluid with your refil kit ? if so take the cart out and soak in a small amount over the rest of tonight, prop it up in some of this fluid in old saucer.
Then or now if you have no ink cleaning fluid, use the lexmark head cleaning tool in the software, not sure if this is on yours though.
So print of about 12 sheet or upto 12 test pages to loosen the cart head up.
just everynow and again lexmark carts will dry up if not used for a while.